The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 2002
Filed:
Sep. 06, 2001
Applicant:
Inventors:
Terry R. Matthias, Upton St. Leonards, GB;
Nigel Dennis Griffin, Nympsfield, GB;
Peter Raymond Hughes, Stroud, GB;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 1/046 ;
U.S. Cl.
CPC ...
E21B 1/046 ;
Abstract
A rotary drill bit includes cutters arranged in a series of concentric rings, the cutters of one of the rings having a different wear resistance to the cutters of another of the rings with the result that the stability of the drill bit improves with wear. Although the wear resistance is different, the cutters have substantially the same impact toughness.